/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.optimize.info;

import proguard.classfile.*;
import proguard.classfile.util.MethodLinker;
import proguard.evaluation.value.Value;

/**
 * This class stores some optimization information that can be attached to a method.
 *
 * @author Eric Lafortune
 */
public class MethodOptimizationInfo {
    protected boolean hasNoSideEffects = false;
    protected boolean hasNoExternalSideEffects = false;
    protected boolean hasNoEscapingParameters = false;
    protected boolean hasNoExternalReturnValues = false;

    public boolean isKept() {
        return true;
    }

    public void setNoSideEffects() {
        hasNoSideEffects = true;
        hasNoExternalSideEffects = true;
        hasNoEscapingParameters = true;
    }

    public boolean hasNoSideEffects() {
        return hasNoSideEffects;
    }

    public void setNoExternalSideEffects() {
        hasNoExternalSideEffects = true;
        hasNoEscapingParameters = true;
    }

    public boolean hasNoExternalSideEffects() {
        return hasNoExternalSideEffects;
    }

    public void setNoEscapingParameters() {
        hasNoEscapingParameters = true;
    }

    public boolean hasNoEscapingParameters() {
        return hasNoEscapingParameters;
    }

    public void setNoExternalReturnValues() {
        hasNoExternalReturnValues = true;
    }

    public boolean hasNoExternalReturnValues() {
        return hasNoExternalReturnValues;
    }

    // Methods that may be specialized.

    public boolean hasSideEffects() {
        return !hasNoSideEffects;
    }

    public boolean canBeMadePrivate() {
        return false;
    }

    public boolean catchesExceptions() {
        return true;
    }

    public boolean branchesBackward() {
        return true;
    }

    public boolean invokesSuperMethods() {
        return true;
    }

    public boolean invokesDynamically() {
        return true;
    }

    public boolean accessesPrivateCode() {
        return true;
    }

    public boolean accessesPackageCode() {
        return true;
    }

    public boolean accessesProtectedCode() {
        return true;
    }

    public boolean hasSynchronizedBlock() {
        return true;
    }

    public boolean returnsWithNonEmptyStack() {
        return false;
    }

    public int getInvocationCount() {
        return Integer.MAX_VALUE;
    }

    public int getParameterSize() {
        return 0;
    }

    public boolean hasUnusedParameters() {
        return false;
    }

    public boolean isParameterUsed(int variableIndex) {
        return true;
    }

    public long getUsedParameters() {
        return -1L;
    }

    public boolean hasParameterEscaped(int parameterIndex) {
        return true;
    }

    public long getEscapedParameters() {
        return -1L;
    }

    public boolean isParameterEscaping(int parameterIndex) {
        return !hasNoEscapingParameters;
    }

    public long getEscapingParameters() {
        return hasNoEscapingParameters ? 0L : -1L;
    }

    public boolean isParameterModified(int parameterIndex) {
        // TODO: Refine for static methods.
        return !hasNoSideEffects && (!hasNoExternalSideEffects || parameterIndex == 0);
    }

    public long getModifiedParameters() {
        // TODO: Refine for static methods.
        return hasNoSideEffects ? 0L : hasNoExternalSideEffects ? 1L : -1L;
    }

    public boolean modifiesAnything() {
        return !hasNoExternalSideEffects;
    }

    public Value getParameterValue(int parameterIndex) {
        return null;
    }

    public boolean returnsParameter(int parameterIndex) {
        return true;
    }

    public long getReturnedParameters() {
        return -1L;
    }

    public boolean returnsNewInstances() {
        return true;
    }

    public boolean returnsExternalValues() {
        return !hasNoExternalReturnValues;
    }

    public Value getReturnValue() {
        return null;
    }

    public static void setMethodOptimizationInfo(Clazz clazz, Method method) {
        MethodLinker.lastMember(method).setVisitorInfo(new MethodOptimizationInfo());
    }

    public static MethodOptimizationInfo getMethodOptimizationInfo(Method method) {
        return (MethodOptimizationInfo)MethodLinker.lastMember(method).getVisitorInfo();
    }
}
